Process for controlling the combustion of fuel.



HENRY J. ,WiLLIAMSJ OF BOSTON, MASSACHUSETTS, ASSIGNOR, lsv Meansrisers-smears,

TO THE GOAL TREATING no, or PHOENIX, ARIZONA TERRITORY, AND nos'ron, MASSA- onusnrrs, A CORPORATION OF. ARIZONA TERRITORY.

rnocnss FOR-CONTROLLING 'rrna, oomnus'rron" on he; steers.

To all whom it may concern:

Be it known that I, HENRY J. WILLIAMS, a citizen of the United States, residing at Boston, in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Processes for Controlling the Combustion of Fuel; and I do herebydeclare the following to be a full, clear, andexact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to a process for controlling the combustion of fuel, and has for. its object the provision of a cheap and certain method for facilitatingthe combustion of coal and at the same time preventing the production of smoke. In the application of Newell W. Bless, Serial No. 433,234, filed May 16, 1908, there is disclosed" a process for accomplishing the above purposes wherein catalytic agents are used, and especially salts of the alkali group'- in thin films; sodium nitrate being preferred. From a series of practical tests carried out by myself, I have discovered thatsalts of the alkaline earths are even more efficient for'this purpose than salts of thealkali metals; especially calcium chlorid CaCl,,'which is probably immediately converted into'calcium oxid CaO,-.a-f ter the fuel is, ignited.

Therefore, my invention consists in coating the fuel, preferably coal, with a thin film of a salt of the alkalineearths, then igniting the fuel and permitting it to generate a combustible gas, which in turn ignites and produces a flame much longer than is produced under the same conditions when the fuel is not so treated.

In carrying out my processl preferably employ a salt which is soluble in water, and coat the fuel with a water solution of the same by either a sprinkling or a dipping process, preferably the latter. After the coal, or other fuel, is thoroughly coated with this solution and allowed to drain, it is then placed upon a fire kindled in the ordinary way. As soon asthe water is driven off and a temperature of about 1000 F. in the fire is reached, blue flames begin to appear which at first gradually increase, and then rapidly grow longer as the temperature rises, until at a temperature in the neighborhood of 1800 B, there exists splendid long flames Specification of Letters Patent. I

Application filed June 10, 1908. Serial No. 437,721.-

Patented. Aug. aaisoe.

very greatly exceeding in volume and length any flames that could possibly be producedund er like conditions if the coal were not coated with the solution mentioned, or its equivalent. in, fact, I have repeatedly produced flames under the abo've conditions which were 36 inches long, or'longer, when under the same conditions the same coal untreated failed to produce flames longer than four inches. pronounced in favor of the treated fuel. I

have, also,tried solutions of calcium chlorid,

CaCh, of various strengths, ranging from one part of CaCl salt to 600 parts of water to one Still other tests were even more.

part' of salt to 10 parts of water, with the most satisfactory results; and these experiments seem to show that a solution of about one part of salt in about 56 parts of water would be the most desirable from a commercial standpoint, owing to the fact that the flames with such a solution are thoroughly satisfactory; and a solution containing one part of salt in 10 parts of water does not give flames five times as great in. volume; and therefore the chemicals consumed in. the i-50 solution are sufficient and about five times as cheap as in the 1-10 solution. Not only are the flames from the treated fuel very much longer than from the untreated fuel, but there appears to be substantially perfect combustion, and therefore practically no smoke is given off. Under properconditions no smoke at'all can be seen to be emitted.

Another advanta e of reat i'zn ortance lies in the fact, that if low grade fuel includ ing coal which is difiicult to ignite, such as the well known graphitic coat-of 'Ehode Island, be treated by my process it becomes results above outlined,because the chemistry of combustion in furnaces together with the reactions that take place therein are so httlc understood; but'it is probable that said results are due to a cataiytic ction of some kind. That is to say, it is possible when the calcium chlorid Cat,

is subjected to a high; temperature in the nice of carbon and Water vapor, that chlorin goes off, the

monoxid gas 00, which leaves the system; whereupon the reduced calcium again takes up oxygen from the air and the process is repeated indefinitely; The carbon monoxid" given off, of course, ignites and burns to 00,, thereby liberating great heat, while those )ortions of the fuel not' covered by the film urn directly to CO, and liberate suflicient heat among the particles of coal themselves to keep up the combustion, as well as the catalytic action.

The behavior of the fuel with a given film of salt will vary with the furnace, thedraft and other conditions, just. as in the cases of ordinary fires; and thereforewhile the above solution of one part of salt in fifty of water, is commercially the best for the conditions under which it was tried, etit might'not be. most economical under w olly different con-. ditions. In all cases, however, only a rela-j tively thin film is necessary, and it often takes some little time after the treated coal isut on the fire before any useful or surprising results begin to ap ear, althoughrI have Tun-v (ler favorable com itions produced such re-' sults in about ten. minutes or less.

While I prefer to use water soluble saltsto obtain the coating, of course, other salts could be used, so lon as the individual lumps arecoated with a t in film. Nor is it necessary that all the fuel be so coated. It suflices if a substantial portion on the fire has been treated,- but, of course, the flames in that case may not be so large.

, After the solution has been drained from the lumps a very small quantity of it-remains stic ing thereto; and after the water has been driven from this small quantity b the heat of the fire, an. exceedingly smal quantity of the chemical remains on the coal, .formin a film'which must be almost infinitesimal y thin.

Of course, I do not limit myself'to the above theory of operation nor to any other theory, since so little is definitely 'known on -it, substantially as describe this subject; but the facts above can best be explained ,by the various catalytic theories found in modern-chemistries, and I believe one 'or more'of them to offer the most satisfactory explanation of the-remarkable results achieved in practice.

What I claim is I 1. The pro ess. of facihtating r'the combu'stion io'ffuel, which consis'tsin coating the same with a thinfilm of a salt of the alkaline earth meta-ls" then igniting said .fuel and permitting said film, when thefuel is burned, to cause carbonto be withdrawn from said fuel and to be set free in, the form of a 'combustible gas, substantiall. 'asdescrib'ed, e '2. The process of facilitating the combustion of fuel, which consists in coating thesame'with a thin film from a solution'of a.

salt of the alkaline earth metals; igniting said land perm'ittin said filmto cause car-. bon to be withdrawn om said fuel and set .free in the form of'a combustible gas, "sub;-

stantially'as, described. 7 3; The process off 'cilitating the combus- 7 .tion of fuel,which consists in treating said fuel with a. solution of calcium chlorid,

allowing said fuel to drain, and then igniting said fue substantially as described.

4. The'process of facilitating the combustion of fuel, which consists in treatin saidfuel with. adilute water solution 'of ca cium chlorid, leaving thereon 'a thin film; and then ignitin r said'fuel, substantially as described.

5. T e 'rocess of-pdntrolling the. combustion of fue which consists immersin said fuel in a dilute water solution of ca cium chlorid draining said fuel" 6. The rocess of'controll ,nd-then igniting.

' he combusout-- one part of calcium chlori' to-fifty parts of water allowing the fuel to drain and then igniting the same, substantially as described.

In testimony whereof, I aflix my signature, I

I HENRY J. Witnesses: 1

JOHN H. ROBINSON, JAMES WJDENNIS.

in presence of two witnesses.

' WILLIAMS. 

